Wyoming, a state known for its vast landscapes and rugged beauty, also holds a reputation for its notably cold winters. Its unique geography and atmospheric conditions combine to create an environment where temperatures can plummet.
Average Winter Temperatures Across Wyoming
Winter temperatures in Wyoming vary considerably by location and elevation, but January is generally the coldest month. Statewide, average minimum temperatures from December through February typically range from 5°F to 18°F. However, this can drop significantly lower in western valleys, where mean minimums can reach around -5°F.
Lower elevations and basins, such as the Bighorn Basin, show distinct temperature patterns. For instance, areas like Worland and Basin, situated around 4,000 feet, have mean minimum temperatures of 0°F in January, while Cody, at nearly 5,000 feet, sees a mean January minimum of 11°F. Mountainous regions consistently record colder temperatures, with lows often falling below zero and highs rarely exceeding 30 degrees Fahrenheit.
Factors Contributing to Wyoming’s Cold Winters
Several geographical and meteorological elements contribute to Wyoming’s cold winters. The state’s high average elevation, often exceeding 6,000 feet, means thinner air that retains less heat, allowing temperatures to drop more severely.
Wyoming’s continental climate, far removed from the moderating influence of large bodies of water like oceans, prevents oceanic warmth from buffering extreme temperature swings. This inland position, coupled with the lack of significant topographic barriers to the north, allows cold Arctic air masses to sweep directly into the state from Canada. Temperature inversions frequently occur in Wyoming’s numerous valleys and basins, where colder, denser air settles at lower elevations and gets trapped by warmer air above. This phenomenon can lead to valley temperatures being significantly colder than those on nearby mountainsides.
Understanding Wyoming’s Record Cold
Wyoming has experienced extreme cold events, setting some of the lowest temperature records in the United States. The state’s all-time record low is -66°F, recorded at the Riverside Ranger Station in Yellowstone National Park on February 9, 1933. This temperature stands as the third-coldest state record documented in the contiguous United States.
Other historically significant cold temperatures include -63°F in Moran on the same date in 1933, and -62°F at Darwin Ranch on February 10, 1981. Recently, Casper broke an all-time record on a December morning, reaching -42°F. These events show the potential for severe cold snaps that extend far beyond typical winter averages.
The Impact of Wind Chill
Wind chill measures how cold people and animals feel outside, accounting for the combined effect of air temperature and wind speed. As wind increases, it rapidly draws heat away from exposed skin, making the perceived temperature feel much colder than the actual air temperature. This phenomenon is particularly relevant in Wyoming due to its windy conditions.
For example, an air temperature of 0°F with a 15 mph wind can result in a wind chill of -19°F, a condition where exposed skin can freeze in just 30 minutes. While wind chill does not lower the actual air temperature, it significantly increases the rate of heat loss from the body, elevating the risk of frostbite and hypothermia. The National Weather Service now issues “Extreme Cold” warnings to encompass both dangerously low temperatures and the intensified cold sensation caused by wind.